Pneumatic transmission systems are typically used to transmit articles from a first location to a second location which is remote from the first location. Pneumatic transmission systems usually include at least two stations, a tube or conduit extending between the two stations and a carrier positioned within the tube so as to be delivered by pneumatic pressure. The pressure can be a subatmospheric pressure or a superatmospheric pressure.
Generally pneumatic transmission systems are used in “drive-thru” terminals for bank facilities, pharmacies, etc., where business is conducted via a carrier transmitted between the bank and the remote “drive-thru” terminal. Other exemplary uses include sending documents between floors in a building, or from one office to another office located some distance apart.
These pneumatic systems include either one or two blowers to create a differential pressure across the carrier to push or pull the carrier from a first terminal within a transmission conduit to a second terminal. In the systems that use one blower, the blower operates to create a vacuum to pull the carrier in one direction and operates to push (create positive pressure) the carrier in the opposite direction. Such continued forward and reverse operations are hard on the blower, which causes these blowers to experience relatively high maintenance requirements and shortened life spans.
In the prior art systems that include two blowers, generally the blowers are separated a substantial distance from the carrier transmission conduit and only connected to the carrier transmission conduit via a secondary conduit system. The blowers either draw or blow air through the secondary conduit system out of or into the carrier transmission conduit system to create the vacuum or positive pressure within the carrier transmission conduit, respectively. The secondary conduit system due to frictional losses requires larger blowers to be used, which unnecessarily increases the cost of implementation and operation of such pneumatic transmission systems.
Additionally, the prior art pneumatic transmission systems include doors to permit the carrier to be inserted or removed from the transmission system at either terminal. These doors are generally configured such that they have large and/or complicated sealing surfaces. Such sealing surfaces on the doors increase the costs of implementation and operation as well as cause sealing issues due to improper seal seating or excessive wear. Also, such conventional systems require additional valve systems to permit air to be drawn into and exhausted out of the transmission conduit, which also increases system reliability issues and maintenance expenses.
Accordingly, there is a need for an improved pneumatic transmission system.